抄録
Offer Organization: Japan Society for the Promotion of Science, System Name: Grants-in-Aid for Scientific Research, Category: Grant-in-Aid for Scientific Research (C), Fund Type: -, Overall Grant Amount: - (direct: 3700000, indirect: -)
We have fabricated and characterized the nano-porous thin films of SiOx grown by Gasevaporation technique in oxygen atmosphere for the application of inter-dielectric in future VLSI technology. It was found that most of the samples had the dielectric constant below 2 as measured by the capacitance method and their porosity were over 90% as measured by the X-ray total reflection method. However, due to high porosity, water absorption into films, measured by FT-IR, was found to be inevitable and resulted in the increase of dielectric constant. In order to avoid this water absorption, we have proposed the HMDS (Hexamethyl disilan) method. We found that the dielectric constant of the film grown at 0.5 torr oxygen atmosphere with HMDS treatment was as low as 1.4. In comparison, we measured the dielectric constant of as-deposited sample in vacuum that was annealed at 623 K and found that it was as low as 1.3. On the other hand, we have fabricated nano-porous thin films of SiOx by post oxidation Si nano-porous grown by Gas-evaporation technique. These samples contained less absorbed water than SiOx samples grown by Gas-evaporation technique in oxygen atmosphere. Typical dielectric constant of these samples were as low as 1.4 without HMDS or high temperature annealing. These results prove that our SiOx films grown by simple Gas-evaporation technique are versatile and can be applied to future VLSI technology without modifying existing systems.